Fastener



Jan. 14, 1.941. R.' FUNK 2,228,760

FASTIENER Filed Feb, 7, 1939 f INVENTOR ATTORNEY Patented Jan. 14, 1941 PATENT OFFICE FASTENER Rudolph Funk, Hagerstown, Md., assig'nor to Fairchild Engine and Airplane Corporation, New York, N. Y., a corporation of Maryland Application February 7, 1939, serial No. 254,992

3 Claims.

This invention relates to fastening devices and has as its principal object the' provision of fastening devices which are self locking, inexpensive, simple to operate andwhich are under spring tension when closed, thereby acting to eliminate or reduce vibration and rattling of the fastening.

Fasteners embodying the present invention are characterized by a rotatable locking stud having lugs projecting therefrom which cooperate with resilient camming and locking elements to draw the members to which they are secured into and retain them in tight relationship. More particularly, the camming elements may consist of springs having an inclined portion terminating in a downwardly offset portion and an upwardly bent portion forming a stop shoulder. With this construction, the stud may be rotated to cause the lugs thereon to engage and move along the inclined portions of the cam surfaces, compressing the springs until the lugs snap into the offset portions and the stop shoulders prevent further rotation of the studo When the fastening devices are connected, the springs are under tension and thus lock the stud in place. At the same time they exert a resilien'l pressure and tend to vention, reference may be` had to the accompanying drawing, wherein:

Figure 1 is a side view of a typical form oi fastening device embodying the present invention with supporting members shown in section and the fastening device in closed position;

Figure 2 is an end view of the fastening device shown in Figure i;

Figure 3 is a view in elevation of the fastening device;

Figure is a side view showing the fastening device with the cooperating elements disengaged.

The form of fastening device disclosed in the drawing is illustrated as applied to two sheets of metal I@ and Il, although it may be applied to any shape or type of members that may desirably be connected. y Referring to Figures 1 and fi, member lll carries a locking stud i2 which is rotatably mounted within a bushing, I3. The bushing I3 is fixed to the member It and engages For a more complete understanding of this inin a groove I4 in the stud I2 to retain the stud in member I0. Stud I2 has a slotted head I5 for receiving a screw driver to rotate it and is provided with oppositely directed lugs I6 at its inner end. Other forms of heads I5 may be pro- 5 vided as the purpose demands. n

As shownin Figure 4, member II is provided with a pair of springs ii and I8, whichcooperate with the stud I2 to lock the members I0 and Ii together. Each of the springs I7 and I8 is geni@ erally S-shaped in plan, as shown in Figure 3, and is provided with an inclined portion I9 of generally helical shape substantially concentric with the axis of the stud I2. At the outer end of the inclined portion I9 the springs are provided 15 with a reversely curved portion formed by bending the springs inwardly to form an offset or depressed portion 20 and then outwardly to form a shoulder 2i which acts as a stop to vprevent Vover-rotation of the stud i2.

The springs Ii and It may be attached to member i I in any desired way, such as by means of rivets 22 passing through loops 23 in the ends of the springs. 'The springs overlie a portion of the member Il with the inclined portion It 25 substantially concentric with an aperture il@ therein through which the stud I2 is passed.

To operate the fastening device, and with thel parts in the position shown in Figure d, the stud i2 is inserted through the aperture 2li and 3o rotated. The lugs It engage the inner ends of the inclined portions i9 and ride up them, at the same time moving the members I@ and Il into engagement. Upon continued rotation of the stud i2, the springs i and I8 are compressed 35 and the lugs i6 move into the onset or depressed portions 2d and against the shoulders Zi. The tension of the springs tends to retain the lugs Iii in the offset portions 2d, as shown in Figures 1 to 3. Rotation'of the stud I 2 in the opposite 4@ direction frees the members i@ and II for separation.

It will be understood that the shape and proportions of the fastening device may be varied as the purpose demands and that it may be used a5 for detachably and resilientiy connecting ali types of members or elements to each other. Therefore, the fastening device described should be considered as illustrative and not as'limiting the scope of the following claims.

I claim:

l. .in a device for detachably connecting a plurality of members, the combination of an element rotatably mounted on one of said mem-l bers and having a laterally projecting lug there- 55 spring having one end portion engaging flatly against said second member, a central cam portion inclined outwardly from 'said end portion at least partially concentric with said element, a reversely curved portion adjacent the outer end of said cam portion forming an inwardly directed oiset and an outwardly directed stop shoulder and another end portion inclined from said stop shoulder inwardly toward and xed to said member whereby upon rotation of said element .the lugs move along `the helical portions compressing the springs and drawing the members together and engage in the offset and against the stop shoulder to lock the element against further rotation and maintain it under tension.

3. In a device for detachably connecting a' plurality of members, the combination of a stud having laterally projecting lugs thereon rotatably mounted on one member and insertable through an aperture in a second member, a pair of springs disposed on the side of the second member away from `said one member and partially overlying said aperture, each spring having one end portion engaging ilatly against said second member, a central cam portion inclined outwardly from said end portion and at least partially concentric with said aperture, a reversely curved portion adjacent the outer end of said cam portion forming an inwardly directed oftset portion and an outwardly directed stop shoulder and another end portion inclined from said 20 stop shoulder inwardly toward and xed to said second member.

' RUDOLPH FUNK 

